Friday, June 19, 2009

JavaFX Datatypes


var s1 = 'Hello';
var s2 = "Hello";

embed expression

def name = 'Joe';
var s = "Hello {name}"; // s = 'Hello Joe'

expression within expression

def answer = true;
var s = "The answer is {if (answer) "Yes" else "No"}"; // s = 'The answer is Yes'

join and concatenate

def one = "This example ";
def two = "joins two strings.";
def three = "{one}{two}"; // join string one and string two
println(three); // 'This example joins two strings.'

Number and Integer

def numOne = 1.0; // compiler will infer Number
def numTwo = 1; // compiler will infer Integer

explicit variable declaration

def numOne : Number = 1.0;
def numTwo : Integer = 1;


var isAsleep = true;

Duration (The Duration type represents a fixed unit of time (millisecond, second, minute, or hour.))

5ms; // 5 milliseconds
10s; // 10 seconds
30m; // 30 minutes
1h; // 1 hour

Void and Null

function printMe() : Void {
println("I don't return anything!");

function checkArg(arg1: Address) {
if(arg1 == null) {
println("I received a null argument.");
} else {
println("The argument has a value.");

More of this here

Sequencing in JavaFx

def weekDays = ["Mon","Tue","Wed","Thu","Fri"];

explicitly specifying sequence type

def weekDays: String[] = ["Mon","Tue","Wed","Thu","Fri"];

Sequence within Sequence

def days = [weekDays, ["Sat","Sun"]];

compiler treats this as

def days = ["Mon","Tue","Wed","Thu","Fri","Sat","Sun"];

shorhand notation for sequence

def nums = [1..100];

more of this in here

java fx at a glance

The JavaFX Script programming language lets you create modern looking applications with sophisticated graphical user interfaces. It was designed from the ground up to make GUI programming easy.

We will be declaring variables like

def a;
def b;
var ag;

calling the function like


function can be written as

function add(){
statement1 ;
statement 2;

passing parameter to the function as

function add(arg1: Integer, arg2: Integer){
statement1 ;

function with return statements

function add(arg1: Integer, arg2: Integer) : Integer{
statement1 ;
return result;

command line arguments

function add(arg: String[]){

def a = java.lang.Integer.parseInt(arg[0]);
def b = java.lang.Integer.parseInt(arg[1]);


Object is created by

Address {
street: "1 Main Street";
city: "Santa Clara";
state: "CA";
zip: "95050";

assigning to a variable

def myAddress = Address {
street: "1 Main Street";
city: "Santa Clara";
state: "CA";
zip: "95050";

nesting object inside another

def customer = Customer {
firstName: "John";
lastName: "Doe";
phoneNum: "(408) 555-1212";
address: Address {
street: "1 Main Street";
city: "Santa Clara";
state: "CA";
zip: "95050";

instance function can be invoked by


Saturday, June 13, 2009

Best way to source control - Tortoise SVN

Hi Recently I heard about this source controlling software which is very light and easy to use..

Mapped to an online repository now we are able to source control out projects on the move with all new , Tortoise SVN.

First, we need to create an empty folder and inside this we have to right click and say 'Create Repository here'

Now Click on the 'SVN checkout' and enter the host name for the repository and the checkout directory.

Now we will be connected to the repository.

After this we are allowed to access the online repository with all common source controlling options on the move.

Friday, June 12, 2009

Know some hashcodes

Some of the hashcodes of interest's are in java wrappers

Boolean - hashCode() - 1231 for 'true' and '1237' for 'false'
Integer - hashCode() - will return the primitive int value
Byte - hashCode() - primitive int value of the byte is returned as hashcode
Charater- hashCode() - primitive int value of the byte is returned as hashcode
Long - value of the following expression


Magic.. Magic..

Ever wonder how files are identified correctly as jpeg, gif or even class file for that matter by the OS.

Its all magic.. :)

Magic numbers are those which are prefixed at the start of the file in ASCII code to identify the file format.

Some of the common magic numbers are

Class bytecode starts with hex
GIF image files have 'GIF89a' (47 49 46 38 39 61) or 'GIF87a' (47 49 46 38 37 61)
JPEG image files begin with FF D8 and end with FF D9
PNG image files begin with "\211 P N G \r \n \032 \n" (89 50 4E 47 0D 0A 1A 0A)
ZIP files begin with 'PK' (50 4B)
PDF files start with '%PDF' (25 50 44 46)